Problem: Expand.
Explanation: We expand the parentheses using the distributive property : $ A(B+C)= A\cdot B+ A\cdot C$ We can also think about the problem using an area model: $b^3$ $-8$ $4b^2$ Here's how the solution goes, algebraically: $\begin{aligned} &\phantom{=}{4b^2}(b^3-8) \\\\ &={4b^2}(b^3)+{4b^2}(-8) \\\\ &=4b^5-32b^2 \end{aligned}$ Here's how the solution looks in terms of the area model: $4b^5$ $-32b^2$ $b^3$ $-8$ $4b^2$ In conclusion, $4b^2(b^3-8)=4b^5-32b^2$